The quincunx: history and mathematics

Received: December 30, 1999; revised version: July 19, 2000     

Norms,status and the dynamics of advice networks: A case study

The issue of the influence of norms on behavior is as old as sociology itself. This paper explores the effect of normative homophily (i.e. “sharing the same normative choices”) on the evolution of the advice network among lay judges in a courthouse. 0020 and 0025 social exchange theory suggests that members select advisors based on the status of the advisor. Additional research shows that members of an organization use similarities with others in ascribed, achieved or inherited characteristics, as well as other kinds of ties, to mitigate the potentially negative effects of this strong status rule. We elaborate and test these theories using data on advisor choice in the Commercial Court of Paris. We use a jurisprudential case about unfair competition (material and “moral” damages), a case that we submitted to all the judges of this court, to test the effect of normative homophily on the selection of advisors, controlling for status effects. Normative homophily is measured by the extent to which two judges are equally “punitive” in awarding damages to plaintiffs. Statistical analyses combine longitudinal advice network data collected among the judges with their normative dispositions. Contrary to what could be expected from conventional sociological theories, we find no pure effect of normative homophily on the choice of advisors. In this case, therefore, sharing the same norms and values does not have, by itself, a mitigating effect and does not contribute to the evolution of the network. We argue that status effects, conformity and alignments on positions of opinion leaders in controversies still provide the best insights into the relationship between norms, structure and behavior.     

The roller-coaster of experiences: becoming the parent of a deaf child

When early testing indicates a hearing loss, parents find themselves on a roller-coaster of experiences leaving little time or space for reflection. This study is based on interviews with families in the Flemish region of Belgium, one of the earliest in the world to introduce universal neonatal screening for hearing loss. Starting from a phenomenological approach, we explore parents’ accounts of their experiences in order to uncover the meanings of early parenting of a child identified with a label. Soon after birth, these parents encounter a different world in which intertwined discourses construct parenthood with a deaf child. During the process of becoming a parent, representations of deafness as impairment were omnipresent. In contrast to a medical and technological perspective that insists on the need to intervene as fast as possible, it is argued that the private and social implications of rapid intervention require explicit consideration.     

Editorial

Ohne Zusammenfassung     

Mixed contracts for the newsvendor problem with real options and discrete demand

In this paper we consider the newsvendor model with real options under discrete demand. We consider a mixed contract where the retailer can order a combination of q units subject to the conditions in a classical newsvendor contract and Q real options on the same items. We provide a closed form solution to this mixed contract when the demand is discrete and study some of its properties. In particular we demonstrate that a mixed contract may be superior to a real option contract when a manufacturer has a bound on how much variance she is willing to accept.     

A technique for comparing graphical methods

The problem of assessing the merit of a technique for displaying data is addressed. The divergence, a measure of the difference between two graphs, is introduced and its properties discussed. The performance of the divergence is investigated by Monte Carlo methods. Two applications of the divergence are presented.     

When is a curve an outlier? An account of a tricky problem

ABSTRACT The analysis of a set of data consisting of N short (≤20 observations each) multivariate time series, where the observations are irregularly spaced and where observations for the different components of each multivariate series are observed at different times, is discussed. With the increased use of automatic recording devices in many fields, data such as these, which are of course samples from smooth response curves, are becoming more common. In this application, which was a clinical trial comparing two cements for use in hip replacement surgery, the key to the analysis was in recognizing that the interest lay in the degree to which the five curves representing a patient's vital signs deviated from baseline (i.e., normal for that patient) during surgery. This enabled the statisticians to define appropriate response variables. The analysis included Rosseeuw's (1984) technique for the identification of multivariate outliers and logistic regressions to identify any effects on the process producing the outliers due to treatment or covariates.     

EMPIRICAL INFLUENCE FOR ROBUST SMOOTHING

A simple graphical method is presented to display the sensitivity of a scatter plot smoother (e.g. loess, kernel smoothers) to perturbations in the data. This enables the robustness of smoothers which have been designed to be robust to be examined directly in particular examples. Graphs are shown of various robust smoothers on several standard datasets, so that the robustness of the smoothers can be compared. The method is found to be useful in revealing features of the smoothers. Related graphs for displaying the sensitivity of a smoother to k > 1 outliers are also presented.     

What Works in Group Care? - A Structured Review of Treatment Models for Group Homes and Residential Care

This paper presents findings from a structured review of treatment models that are relevant to group care and residential treatment settings for children involved with the child welfare system. Initiated and guided by The California Evidence-Based Clearinghouse for Child Welfare, five treatment models — Positive Peer Culture, Teaching Family Model, Sanctuary Model, Stop-Gap Model, and Re-ED — were reviewed for effectiveness. In this paper, each model's treatment features are described and relevant outcome studies reviewed in terms of their effectiveness as well as relevance for child welfare practice. Findings indicate that four of the models are either supported or promising in terms of evidence for effectiveness. Implications for group care practice and research are discussed.